Many people in the building performance field know about a certain, easy-to-perform air flow test that involves common household items. If you are not among them, read on. If you already know about the garbage bag air flow test read on anyway—you might learn something new about it. To perform the test, take a garbage bag, a wire coat hanger that you don’t hang clothes on, some adhesive tape, and a watch. Bend the coat hanger into a circle, square, or rectangle big enough to fit completely around the register where you want to measure air flow. Fit the opening of the garbage bag around the coat hanger and tape it in place (you don’t have to make it tight, just so it stays on the hanger).Now you have the necessary technology.The biggest challenge for those who are technologically inept is how to avoid poking a hole in the garbage bag with the coat hanger.The authors welcome any tips regarding this point. Put the completely deflated garbage bag rig that you’ve ...